Table 1 Comparison between the right side and left side according to different variables in total sample

FR distance to the midline (cm)

1.71 ± 0.21

1.81 ± 0.22

Z=4.185^*

<0.001^*

Horizontal distance FR to VC (mm)

4.61 ± 1.62

4.73 ± 1.64

t=0.723

0.471

Vertical distance FR to VC (mm)

3.99 ± 1.80

4.12 ± 1.89

Z=0.641

0.521

Direct distance FR to VC (mm)

5.40 ± 2.25

5.71 ± 2.39

t=1.817

0.072

Diameter of FR (mm)

3.15 ± 0.55

3.15 ± 0.79

Z=1.073

0.283

FR angle (degree)

47.51 ± 10.65

47.57 ± 9.51

t=0.060

0.952

Distance between anterior nasal spine to FR (cm)

6.22 ± 0.46

6.30 ± 0.50

t=2.001^*

0.048^*

Angle between nasal floor and FR (degree)

29.13 ± 6.56

29.37 ± 5.76

t=0.440

0.661

Distance between optic nerve and FR (cm)

1.74 ± 0.20

1.75 ± 0.19

t=0.437

0.663